Optical components are generally used for telecommunication and data transfers over networks. Variable in-line optical attenuators (also referred to as adjustable in-line optical attenuators) may provide fixed control of optical power levels of an optical signal in a controlled manner when placed in its optical path.
Generally, variable (or different levels of) in-line attenuation can be achieved in a variety of ways. One way is to attenuate the output light from one optical fiber with a filter or a doped fiber, which then enters a second optical fiber to produce the attenuated light. The amount of attenuation is dependent on the density of the filter or amount of doping of the fiber, which can be changed across different parts to achieve different levels of attenuation.